Pressure Spikes: Survey on Charge Pump Overshoot

Survey: What are your peak charging pressures / overshoots?

With this survey, I want to achieve a situation where we all here in the forum have a general overview.
What kind of pressure peaks/overshoots are we experiencing here in the forum?
It would be nice to have a brief overview.
That might solve the problem for some people, allowing them to post a question directly.

'For this, the pressure peaks/overshoots should be specified in bar.'
What kind of engine do you have?
Whether you have a chip/tuning module/OBD tuner/or are running the stock engine.
and whether any other modifications were made to the exhaust system, etc.


I hope at least some of you will support and participate in this survey.

Dear TDI greetings from Carinthia.

Hi.

My car is downstairs... The exhaust is stock, but I have a larger intercooler installed.

The overpressure valves typically go up to a maximum of 1.2 bar, but with an active enclosure, they can sometimes reach up to 1.4 bar.

However, when abruptly releasing the accelerator after strong acceleration at low engine speeds (down to about 1400 rpm), I sometimes hear a noise like "scrape-scrape-scrape," and the LDA (likely referring to a gauge or indicator) needle drops in a stepwise manner at the same rhythm.

I suspect the cause is airflow noise from some air column separations within the supercharger, as I can't manually tilt the supercharger turbine far enough to cause it to rub against anything.

I've been wanting to twist the VTG rod to a slightly gentler pressure build-up = less overshoot, in hopes of eliminating the noise, but whenever I have time, I never seem to think about it.

Engine AHF.
Additional box.
Boost pressure increased to 1.15-1.2 bar, standard is 1.00 bar.
Boost pressure peak: 1.4 bar.

Hi,
Passat Variant. Model 1Z, chip tuning + 10 horsepower, intake manifold optimized, boost pressure with chip 1.1 bar, overboost up to 1.4 bar.

A4 AWX (130 hp, direct injection). Standard value: 1.45-1.48. Peak value: 1.53. Chip from MTH.
Best regards, Jussi.

Hey everyone!

Thank you for participating in the survey!
I think that's really cool of you guys!

Hi,

Engine ASV (81KW), currently with 19,000 km on the clock, but without a boost pressure gauge. About 10,000 km ago, I logged several full-throttle accelerations in 3rd gear using VAG-COM, and the peak boost pressure reached up to 2150 mBar absolute, which is 1.15 bar according to the usual measurement method.



The green curve represents [something], the blue line shows the position of the magnetic valve for the turbocharger pressure, and the red line, of course, indicates the engine speed.

"About 1240 kilograms of car were hanging from it, and I had the accelerator pedal pressed all the way down. The engine is and remains untuned, and the EGR system is functioning correctly."

Best regards,

Jan.

As they say, a picture is worth a thousand words, so here's a picture:
http://www.hmi.de/bensc/sample-env/pc/Ladedruck.gif
Engine AJM (115 hp, particulate filter), Passat, manufactured in 04/2000. Despite the 5-speed gearbox, it likely has 310 Nm of torque. No chip tuning has been applied, and the AGR (Acoustic Round Vibration) system is working correctly.

Sebastian.